An Air France Airbus A321-200, registration F-GTAN performing flight AF-7633 from Bordeaux to Paris Charles de Gaulle (France), was on final approach to Charles de Gaulle's runway 26L with autopilot and autothrust engaged, when autothrottle disconnected and the speed decayed until the alpha floor protection activated accelerating the engines to takeoff/goaround thrust and disengaging the autopilot. The crew took control, stabilized the aircraft and continued for a safe landing on runway 26R.
The BEA reported in their weekly bulletin of Sep 11th that the autothrust system had disengaged permitting the airspeed to decay to a point where the alpha floor protection activated, disengaged the autopilot and accelerated the engines. The crew took manual control and continued the landing. The BEA is investigating the serious incident.
Beside it's not autothrottle on AB it's AThrust, but if true, how come a flag carrier's crew allows a plane to almost stall?
20 years ago, a crew on approach to a runway would concentrate on their instruments for the approach, then look out of the window once visual for landing.
These days crew stare vaguely out of the window as the automatics fly the approach, then concentrate fiercely on their instruments once visual and hand flying for the landing ...
"Beside it's not autothrottle on AB it's AThrust, but if true, how come a flag carrier's crew allows a plane to almost stall?"
The same flag carrier that actually stalled an aircraft on mid Atlantic whose crew failed to recognize it for more than 3 minutes, crashing in the water.
Sorry guy's but before you start judging.. Something doesn't quite add up. If the A/THR disconnected itself they would get THR LK flashing on the FMA, thrust would be locked and they would have a repetative chime and a ECAM warning.
Look, I don't wanna get into a shallow A vs B debate nor condemn or defend the crew.
Just saying how it is, if the A/THR disconnect was inadvertent than it is pretty hard to miss. A manual disconnect on the other hand is a simple single chime..
We won't say anything about a certain UK charter airline that nearly stalled whilst on approach to Bournemouth a few years ago then?
Fireflybob, the incident which you refer to exposed unexplained and undetected disengagement of the A/T system on the 737. I've had it happen to myself (thankfully detected it - maybe I got lucky - however I had the use of the FMA banged into me from an early stage). Had maintenance carry out a BITE test and a series of observations and nothing resulted. The 737's A/T disengagement annunciating system, as you likely know, is cack and relies heavily on the crew to be monitoring the FMA at all times. I'm not sure about the Bus, however Alpha floor seems to have saved the day. With the BOH incident the aircraft approached the stall, the crew applied TOGA thrust and the resulting pitch power couple stalled the aircraft. I believe this and the unfortunate THY incident at EHAM led to Boeing amending the approach to stall recovery manouvre (unsurprisingly as the one in force at the time made no sense).
Last edited by Callsign Kilo; 12th Sep 2012 at 19:09.
You would usually get thrust lock, and current thrust would be maintained if the athrst failed.
Also, this similiar incident happened at a uk airbus operator sometime last year apparently, so don't be so quick to judge.
At the end of the day, alpha floor did its job and protected the aircraft - its good to see it worked.
Also AF447 is was a very different situation. A crew in a cruise suddenly dropped not downgraded laws. This aircraft on approach would have been in normal law. This is very different.
Last edited by EcamSurprise; 12th Sep 2012 at 19:09.
Fireflybob, the incident which you refer to exposed unexplained and undetected disengagement of the A/T system on the 737. I've had it happen to myself (thankfully detected it - maybe I got lucky - however I had the use of the FMA banged into me from an early stage). Had maintenance carry out a BITE test and a series of observations and nothing resulted. The 737's A/T disengagement annunciating system, as you likely know, is cack and relies heavily on the crew to be monitoring the FMA at all times. I'm not sure about the Bus, however Alpha floor seems to have saved the day. With the BOH incident the aircraft approached the stall, the crew applied TOGA thrust and the resulting pitch power couple stalled the aircraft. I believe this and the unfortunate THY incident at EHAM led to Boeing amending the approach to stall recovery manouvre (unsurprisingly as the one in force at the time made no sense).
Callsign Kilo, I wasn't pointing any fingers and the intention was not to get involved in a systems debate but saying that AF isn't the only operator that has had such incidents. Not saying AF is perfect either!
Kilo, it doesn't matter what type of aircraft or what type of auto throttle/thrust system. As pilots, out primary role in these modern days is to monitor the automatics. Secondary to this is the age old skill of monitoring the instruments. The fact that speed can be allowed to decay so much to the point of stall
is mind boggling. Having said that I wasn't there to witness the event unfold so I cant pass judgement.
During an approach I would say 40% of my attention is on the ASI. Having seen in the sim just how slow a modern jet has to get to actually stall does make me wonder how these events actually occur.
Are these incidents not caused partly by the diminution of basic handling skills due to the increased automation and an up and coming generation of pilots who have little or no experience of hand flying jet aircraft?
When I look back to flying the B737-200 in the 1980s or the B707 in the 1970s I recall that it was quite commonplace for approaches from FL 100 or even (shock horror) from top of descent to be hand flown. We would think nothing of hand flying a visual approach or even a circle to land. We did so much of this that we were "hard-wired" for manual flying - consequently flying the correct airspeed (and the PNF shouting "Airspeed" when the trend or instant value wasn't going the right way) was a given.
I am not against use of automation but I believe this is where the root cause of the problem is. I don't blame the individuals - it is the system (or lack of it) that has produced this result. If we want pilots to be competent they have to be in practice at hand flying but given the dumbing down of basic skills the software/techie guys will seek all sorts of solution with extra warning systems I suppose.
Last edited by fireflybob; 12th Sep 2012 at 19:47.
